Dust-collecting container for a hand electric machine tool

ABSTRACT

A dust-collecting receptacle for an electric hand machine tool, in particular an electric hand grinder, having a dust-collecting chamber ( 17 ), an inlet fitting ( 21 ), an exhaust opening ( 18 ), and a dust filter ( 20 ) situated between the dust-collecting chamber ( 17 ) and the exhaust opening ( 18 ). To achieve a compact design of the dust-collecting receptacle ( 14 ) that on the one hand, does not impair operation of the electric hand grinder or only does so to an insignificant degree and on the other hand, has a high dust-collecting efficiency, the inlet fitting ( 21 ), the dust-collecting chamber ( 17 ), the dust filter ( 20 ), and the exhaust opening ( 18 ) are situated one above another and preferably, the form of the dust-collecting receptacle ( 14 ) is adapted to the outer contour of the electric hand machine tool (FIG.  1 ).

PRIOR ART

The invention is based on a dust-collecting receptacle for a handmachine tool, in particular an electric hand grinder, according to thepreamble to claim 1.

In electric hand grinders, grinding dust is collected in cloth bags,paper bags, or boxes, which have a protruding intake fitting that isfitted onto a dust output fitting on the machine housing. Whereas thepaper bags and cloth bags are designed to be expendables that arediscarded along with the dust that has been collected, the boxes have adust-collecting chamber that can be emptied once the box is opened,which allows the dust-collecting receptacle to be reused. The inletfitting feeds into the dust-collecting chamber and the dust-collectingchamber communicates with an exhaust opening preceded by a dust filter.In the working position of the electric hand grinder, the inlet fitting,the dust-collecting chamber, the filter, and the exhaust opening aresituated one after another in spatial sequence.

ADVANTAGES OF THE INVENTION

The dust-collecting receptacle according to the present invention, withthe characteristics of claim 1, has the advantage that the integrationof the inlet fitting into the dust-collecting receptacle itself and thespatial placement of the inlet fitting, the dust-collecting chamber, thefilter, and the exhaust opening one above the other in the workingposition of the electric hand grinder achieves a compact embodiment ofthe dust-collecting receptacle with a short structural length and highdust-collecting efficiency. At the same time, the concealed placement ofthe inlet fitting makes it possible to produce a more attractivedust-collecting receptacle whose outer contours can be adapted to themachine housing in an optimally designed manner.

Advantageous modifications and improvements of the dust-collectingreceptacle according to claim 1 are possible by means of the measurestaken in the remaining claims.

According to a preferred embodiment of the invention, the mouth of theinlet fitting is located close to the rear delimiting wall of thedust-collecting chamber, at the end facing away from the connectingopening of the inlet fitting and is situated there so that the axis ofthe mouth is oriented toward the delimiting wall. Because of thisstructural measure, the dust advantageously enters into thedust-collecting chamber at its rear delimiting wall and is evenlydistributed throughout the dust-collecting chamber by the flow of air.The uniformity of the dust distribution is further improved in that,according to a preferred embodiment form of the invention, the exhaustopening and the preceding dust filter extend across the entire top ofthe dust-collecting chamber.

According to a preferred embodiment of the invention, thedust-collecting chamber is enclosed by a box-like housing that is openat the top and a cover that seals the housing and can be removed fromit. The inlet fitting is integrated into the housing bottom and theexhaust opening is situated in the cover. The dust filter is attached tothe underside of the cover, preferably by means of ultrasonic welding,and the dust filter is preferably embodied as a folded filter. The inletfitting is conical and tapers from the connecting opening to the mouth,which has a positive impact on the air speed in the inlet fitting and onthe associated transportation of dust.

According to an advantageous embodiment of the invention, locking hooksare provided to engage in corresponding locking recesses in the machinehousing. These locking hooks are preferably injection molded in onepiece onto the side walls of the housing and protrude out from its endsurface oriented toward the machine housing. This structural measurepermits the dust-collecting receptacle to be quickly and convenientlydetached from and reattached to the machine housing again by means of asimple locking action. Elastic sealing rings, which are situated betweenthe inlet fitting of the dust-collecting receptacle and the dust outputfitting of the machine housing, provide a reliable dust seal for thedust-collecting receptacle.

According to an advantageous embodiment of the invention, the cover hasan elastic edge with an air-sealing function, which can be placed ontothe housing. As a result, the cover supporting the dust filter seals thehousing in a dust-tight fashion and can be easily removed from thehousing in order to empty the dust-collecting chamber and then bereattached to the housing.

DRAWINGS

The invention will be explained in greater detail below in conjunctionwith an exemplary embodiment shown in the drawings.

FIG. 1 is a partially sectional side view of an electric hand grinderwith a dust-collecting receptacle attached,

FIG. 2 is a longitudinal section through the dust-collecting receptaclealong the cutting line II-II in FIG. 5,

FIG. 3 is a perspective top view of a cover of the dust-collectingreceptacle according to FIGS. 1 and 2,

FIG. 4 is a perspective top view of a housing of the dust-collectingreceptacle according to FIGS. 1 and 2 that can be closed by the coveraccording to FIG. 3, and

FIG. 5 shows a view of the housing in the direction of the arrow V inFIG. 4.

DESCRIPTION OF THE EXEMPLARY EMBODIMENT

The eccentric grinder, a side view of which is shown in FIG. 1 as anexemplary embodiment for an electric hand grinder, has a machine housing11 whose underside is provided with a backing pad 12 that can beequipped with an abrasive disk and driven to rotate. The grinding dustproduced during grinding is sucked through the backing pad 12 by a fan,not shown here, mounted on the drive shaft of the backing pad 12 and isblown out via a dust output fitting 13 that is formed in one piece ontothe machine housing 11. A dust-collecting receptacle 14 is slid in adust-tight fashion onto the dust output fitting 13.

The dust-collecting receptacle 14 detachably fastened to the machinehousing 11—which receptacle is shown a partial side view in FIG. 1, alongitudinal section in FIG. 2, and detailed views in FIGS. 3 to 5—has abox-like housing 15 (FIG. 4) that is open at the top and a cover 16(FIG. 3), which can be placed onto the housing 15, seals the housing 15in a dust-tight and air-tight fashion and, together with the housing 15,encloses a dust-collecting chamber 17. The cover 16 is provided with anexhaust opening 18 that is covered by a louvered grating 19. When thecover 16 is placed onto the housing 15, the exhaust opening and louveredgrating 19 extend over virtually the entire open top of the housing 15.To produce a dust seal, the cover 16 has an elastic edge 161 extendingaround the outside that has an approximately U-shaped profile and ispressed against the edge of the circumferential end of the housing 15(FIG. 1).

As is clear from FIGS. 1 and 2, a dust filter 20 is attached to theunderside of the cover 16 oriented toward the dust-collecting chamber17. The dust filter 20 is preferably embodied as a folded filter and isattached to the cover 16 by means of ultrasonic welding. An inletfitting 21 is integrated into the bottom of the housing 15 and has aconnecting opening 22 designed to fit onto the dust output fitting 13 ofthe machine housing 11 and a mouth 23 oriented toward thedust-collecting chamber 17. The inlet fitting does not extend over acontour of the receptacle. The inlet fitting 21 is conical and taperscross-sectionally from the connecting opening 22 to the mouth 23. Theconnecting opening 22 is recessed from the end wall 151 that can beplaced against the machine housing 11 and the mouth 23 is situated closeto rear housing wall 152 of the housing 15 at the end oriented away fromthe connecting opening 22, with the axis of the mouth 23 oriented towardthe rear housing wall 152.

Like the cover 16, the housing 15 is manufactured of plastic using theinjection molding process; the inlet fitting 21 extending along thehousing bottom 153 is formed onto the housing 15 as it is beingmanufactured. Two locking hooks 24 (FIG. 4) are also formed in one pieceonto the housing 15, which protrude from the side walls of the housing15 beyond the front end wall 151 and can engage in correspondinglyembodied locking recesses in the machine housing 11.

In order to attach the dust-collecting receptacle 14 to the machinehousing 11, the cover 16 with the dust filter 20 underneath it isclamped onto the housing 15 and the complete dust-collecting receptacle14 thus produced is slid with its bottom inlet fitting 21 onto the dustoutput fitting 13 of the machine housing 11 until the locking hooks 24engage in the corresponding locking recesses in the machine housing 11.Annular seals 26, 27 situated in between the inlet fitting 21 and thedust output fitting 13 produce a dust-tight attachment of thedust-collecting receptacle 14 to the dust output fitting 13.

During operation of the electric hand grinder, the dust-laden air flowthat the rotating fan in the machine housing 11 sucks through thebacking pad 12 and blows out through the dust output fitting 13 is fedinto the inlet fitting 21 and enters the dust-collecting chamber 17close to the rear housing wall 152 of the housing 15. The air flowtravels through the dust-collecting chamber 17 and, passing through thedust filter 20, exits the dust-collecting receptacle 14 via the exhaustopening 18. The dust filter 20 retains the dust and the dust settles inthe dust-collecting chamber 17. The large-surfaced design of the exhaustopening 18 and the location of the mouth 23 of the inlet fitting 21assure a largely uniform depositing of the dust in the dust-collectingchamber 17.

As is clear from FIG. 2, the inlet fitting 21, the dust-collectingchamber 17, the dust filter 20, and the outlet opening 18 are situatedone above another in the working position of the electric hand grinder,as a result of which the dust-collecting receptacle 14 is very compactand does not hinder the operation of the electric hand grinder or impairit in any other way. The dust-collecting receptacle 14 attaches to themachine housing 11 in a secure and reliable fashion thanks to thelocking hooks 24 and the way that the front end wall 151 of the housing15 is designed to rest against the machine housing 11 in a form-lockedfashion when the locking hooks 24 engage. If the form of the housing 15with the cover 16 is also adapted to the outer contours of the machinehousing 11, then this yields an optimally designed unit comprised of theelectric hand grinder and dust-collecting receptacle 14.

The dust-collecting receptacle 14 described above is suitable not onlyfor use with the electric hand grinder described, but also with anyelectric hand machine tool for material-removing machining of workpieces in which material is removed from the work piece as the workpiece is machined. Other examples of such electric hand machine toolsinclude electric hand planes or electric hand saws.

1. A dust-collecting receptacle for an electric hand machine tool, inparticular an electric hand grinder, having a dust-collecting chamber(17), having an inlet fitting (21) that has a connecting opening (22) tobe fitted onto a dust output fitting (13) of the machine and a mouth(23) oriented toward the dust-collecting chamber (17), having an exhaustopening (18), and having a dust filter (20) situated between thedust-collecting chamber (17) and the exhaust opening (18), wherein theinlet fitting (21) extends only inside the receptacle in a lower regionof the receptacle and does not extend over a contour of the receptacleand extends below the dust collecting chamber (17) and below the dustfilter (20) and exhaust opening (18), so that an upper region of theinlet fitting (21) forms a bottom portion of the dust-collecting chamber(17), and wherein the mouth (23) of the inlet fitting (21) is situatedclose to a rear delimiting wall (152) of the dust-collecting chamber(17), wherein said rear delimiting wall (152) is oriented to the axis ofthe inlet fitting (21) with an angle of less than 90° to form a slope toguide an incoming airstream upwards into the dust collecting chamber(17).
 2. The receptacle as recited in claim 1, wherein thedust-collecting chamber (17) extends beyond the connecting fitting (23)of the inlet fitting (21).
 3. The receptacle as recited in one of claim1, wherein the dust-collecting chamber (17) is enclosed by a box-shapedhousing (15) that is open at the top and a cover (16) that closes thehousing (15), the inlet fining (21) is integrated into the housingbottom (153), and the exhaust opening (18) is situated in the cover(16).
 4. The receptacle as recited in claim 3, wherein the exhaustopening (18) extends over the entire cover (16) and is covered by alouvered grating (19).
 5. The receptacle as recited in claim 3, whereinthe dust filter (20) is attached to the underside of the cover (16),preferably by means of ultrasonic welding.
 6. The receptacle as recitedin claim 3, wherein the cover (16) has an elastic edge extending aroundthe outside, which rests against the housing (15) and has an air-sealingfunction.
 7. The receptacle as recited in claim 3, wherein the housing(15) is provided with locking hooks (24) that engage in correspondinglocking recesses provided on the machine.
 8. The receptacle as recitedin claim 3, wherein the housing (15) with the cover (16) is adapted tothe outer contours of the machine.
 9. The receptacle as recited in claim7, wherein the end wall (151) of the housing (15) bounded by the lockinghooks (24) is designed to rest against the machine in a form-lockedmanner.
 10. The receptacle as recited in claim 1, wherein the dustfilter (20) and exhaust opening (18) are situated one above the other ontop of the dust-collecting chamber (17).